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Analysis of arterial and venous blood gases in healthy gyr falcons (Falco rusticolus) under anesthesia.

Abstract: Arterial and venous blood gas analysis is useful in the assessment of tissue oxygenation and ventilation and in diagnosis of metabolic and respiratory derangements. It can be performed with a relatively small volume of blood in avian patients under emergency situations. Arterial and venous blood gas analysis was performed in 30 healthy gyr falcons (Falco rusticolus) under anaesthesia to establish temperature-corrected reference intervals for arterial blood gas values and to compare them to temperature-corrected venous blood gas values with a portable point-of-care blood gas analyzer (i-STAT 1, Abbott Laboratories, Abbott Park, IL, USA). Statistically significant differences were observed between the temperature-corrected values of pH, partial pressure of carbon dioxide ([Pco.sub.2]), and partial pressure of oxygen ([Po.sub.2]) and the corresponding nontemperature-corrected values of these parameters in both arterial and venous blood. Values of temperature-corrected pH, temperature-corrected [Pco.sub.2], bicarbonate concentrations, and base excess of extra cellular fluid did not differ significantly between arterial and venous blood, suggesting that, in anesthetized gyr falcons, venous blood gas analysis can be used in place of arterial blood gas analysis in clinical situations. Values for hematocrit, measured by the point-of-care analyzer, were significantly lower compared with those obtained by the microhematocrit method.

Key words: arterial blood gas, venous blood gas, temperature-corrected pH, temperature-corrected [Pco.sub.2], avian, gyr falcons, Falco rusticolus

Introduction

Analysis of blood gases and electrolytes to assess tissue oxygenation, acid-base balance, and breathing efficiency is important in veterinary critical care of both mammals and birds. Because of a diminished cardiac output, patients in shock may present with a ventilation-perfusion mismatch, with lowered end-tidal carbon dioxide measurements that no longer correlate with the arterial partial pressure of carbon dioxide ([Pco.sub.2]). (1) A weak pulse signal seen in hypovolemic patients may compromise monitoring of arterial hemoglobin saturation by pulse-oximetry. Blood gas analysis is a useful tool to assess oxygenation and ventilation in these emergency situations. (2) Blood gas analysis has also been reported to have a diagnostic value in birds with diseases of the lower respiratory tract. (3) Furthermore, in emergency situations, when detailed diagnostic tests are postponed to stabilize the patient, blood gas analysis facilitates rapid diagnosis of metabolic and respiratory derangements from a small volume of blood, allowing prompt therapeutic decision making. The i-STAT 1 handheld analyzer (Abbott Laboratories, Abbott Park, IL, USA) requires [less than or equal to] 0.2 mL of blood and results are available within 2 minutes. Venous blood gas analysis reflects the acid-base balance at a cellular level, whereas arterial blood gas analysis provides information about ventilation, tissue perfusion, and the efficiency of respiratory gas exchange in the lungs. (4,5)

Blood gas parameters have been investigated in different species of birds, including chickens, ducks (Anas species), pigeons, psittacine birds, passerine birds, and various species of raptors, including falcons (Falco species), although varying protocols, investigation methodologies, and analyses were used. (2-19)

During events such as travel and falconry training, falcons are exposed to extreme stress, partial or complete starvation, and water restriction as well as to infectious and metabolic diseases. Assessing acid-base balance can be an important tool in the diagnostic evaluation and therapeutic intervention of critically ill falcons. Diseases of the respiratory system, including bacterial and fungal infections of the lower respiratory tract, are very common presentations in hunting falcons and evaluating the efficiency of respiratory gas exchange would be an effective adjunct to a more-detailed diagnostic workup.

Venous blood gases have been investigated previously in falcons. (9,12) However, those studies did not correct for body temperature in the blood gas analysis and did not provide any reference intervals for arterial blood gas values in falcons. Correction for temperature is crucial for achieving accuracy in blood gas analysis, especially with pH, [Pco.sub.2], and partial pressure of oxygen ([Po.sub.2]). (4) Since the pH of a blood sample decreases as the sample temperature increases, temperature correction is important in the analysis of avian samples, especially because birds have a relatively higher body temperature compared with mammals. (20) Oxygen-binding affinity of hemoglobin is also reported to be modulated by temperature and pH to varying degrees in different species of mammals and birds. (21) In this context, many point-of-care analyzers measure pH, [Pco.sub.2], and [Po.sub.2] directly, whereas other parameters, like the percentage of hemoglobin saturated with oxygen ([So.sub.2]), bicarbonate concentration (HC[O.sub.3.sup.-]), base excess of extracellular fluid (BE), and total carbon dioxide concentration ([Tco.sub.2]), are further derived from the direct values. While [So.sub.2] is derived from [Po.sub.2] and the oxygen-dissociation curve, HC[O.sub.3.sup.-], [Tco.sub.2], and BE are derived mathematically by built-in formulas and nomograms. (4)

Evidence is conflicting in human medicine regarding the suitability of replacing arterial blood gas analysis with venous blood gas analysis in emergency cases. Although there is a broad consensus that venous pH, bicarbonate, and BE values can be substituted clinically in place of arterial values, some researchers suggest that venous [Pco.sub.2] does not sufficiently estimate arterial [Pco.sub.2]. (22,23) To our knowledge, no such studies have been conducted in falcons.

The objective of the current study was to establish temperature-corrected reference intervals for arterial blood gas parameters and to compare them with temperature-corrected venous blood gas parameters in healthy gyr falcons (Falco rusticolus) maintained under isoflurane anaesthesia.

Materials and Methods

Thirty female gyr falcons, 5-18 months old, were selected for the current study. All birds were determined to be clinically healthy based on results of a complete physical examination under manual restraint and a detailed physical and clinicopathologic examination while under anesthesia, as described below. The falcons were not being trained for falconry at the time of the study and were housed indoors in standard aviaries maintained at 20[degrees]-24[degrees]C (68[degrees]-75[degrees]F) and fed a diet of commercially available frozen quail.

For anesthesia, the birds were mask induced with 5% isoflurane at an oxygen flow rate of 1 L/ min and maintained at 3% isoflurane with a Bain nonrebreathing circuit. Manual-assisted ventilation was not provided for any of the birds, and all the birds in the current study were on spontaneous ventilation. Cloacal temperature was recorded at the time of induction with a digital thermometer placed in the cloaca. Blood samples (0.3 mL each) were collected from both the aseptically prepared ulnar artery and the brachial vein into lithium heparin tubes with minimal delay between the 2 samples and immediately submitted for blood gas analysis to an in-house laboratory where they were processed within 5 minutes.

To determine whether the birds were clinically healthy, they were intubated with uncuffed endotracheal tubes, and venous blood samples were collected again from the brachial vein for a complete blood cell (CBC) count and a biochemical profile. Whole-body radiographs were taken in ventrodorsal and lateral projections, and endoscopic examination through the caudal thoracic air sacs was performed on both the left and right sides by standard techniques. All the birds recovered from anesthesia uneventfully.

The arterial and venous samples for blood gas analysis were analyzed with the i-STAT 1 portable point-of-care blood gas analyzer and the Yetscan i-STAT CG8+ cartridges (Abaxis, Union City, CA, USA). The CG8+ cartridges were selected because their software is incorporated with a built-in mathematical formula for temperature correction based on human samples, and the machine output provides values of pH, [Pco.sub.2], and [Po.sub.2] with and without temperature correction. Each cartridge was removed from cold storage only 5 minutes before its use, as recommended. (20) Each sample was analyzed at the corresponding bird's cloacal temperature. In addition, hematocrit was separately measured in each sample by the microhematocrit centrifugation method (Biofuge Haemo, Heraeus Instruments GmbH, Hanau, Germany) to compare with the hematocrit results obtained from the i-STAT 1 analyzer.

Statistical analysis was performed with MedCalc statistical software (MedCalc Software, Ostend, Belgium). The Kolmogorov-Smirnov test was used to determine the distribution of the data. To determine reference interval parameter values, the 2-sided tolerance interval was calculated for normally distributed data, and the distribution-free 2-sided tolerance interval was used for other values. Statistical significance was set at P < .05. Comparison between values of temperature-corrected and nontemperature-corrected parameters was performed by the paired t test for normally distributed data and the Wilcoxon matched-pairs signed-rank test for nonparametric data. Bland-Altman plots were calculated to compare temperature-corrected venous and arterial values of pH, [Pco.sub.2], and [Po.sub.2] to determine the agreement between the 2 methods.

Results

The results of the arterial and venous blood gas analysis are shown in Table 1. Temperature-corrected values differed significantly from nontemperature-corrected values of pH (P < .01), [Pco.sub.2] (P < .001), and [Po.sub.2] (P < .001) in both arterial and venous samples.

No significant differences were found in venous samples compared with arterial samples in temperature-corrected values of pH and [Pco.sub.2]. However, temperature-corrected [Po.sub.2] values of the venous blood samples differed significantly from the corresponding arterial values (P < .001). Bland-Altman plots for pH (mean [+ or -] SD, -0.0074 [+ or -] 0.0528) and [Pco.sub.2] (-1.12 [+ or -] 5.94) (Figs 1 and 2) indicate that, in both cases, the venous values slightly underestimated the arterial values. However, the bias and the 95% limits of agreements did not seem to be relevant from a clinical perspective. The venous [Po.sub.2] (-62.72 [+ or -] 31.71) (Fig 3), also underestimated the arterial value, but, in this case, the bias and the limits of agreement seemed to be important from a clinical perspective.

No significant differences were found between values of HC[O.sub.3.sup.-], BE, [Tco.sub.2], [K.sup.+], ionized calcium, glucose, hematocrit, and hemoglobin concentrations between arterial and venous blood samples. However, significant differences were found in sodium ([Na.sup.+]) (P < .001) and the percentage of [So.sub.2] (P < .001) when the values obtained from venous blood were compared with those obtained from arterial blood.

Hematocrit values in venous blood differed significantly (P < .001) between samples measured with i-STAT 1 (42.1% [+ or -] 4.0%) and those measured by the microhematocrit method (51.9% [+ or -] 2.7%).

Discussion

Gyr falcons are one of the most common species used in falconry in the Middle East because of their speed, agility, and ability to hunt large prey. Analysis of arterial and venous blood gases and electrolytes is an important aid in avian emergency medicine. This study was conducted to establish reference intervals for arterial blood gas values in healthy gyr falcons under isoflurane anesthesia and to evaluate the importance of using temperature-corrected values of pH, [Pco.sub.2], and [Po.sub.2] for accurate arterial and venous blood gas analysis in birds.

Only falcons determined to be clinically healthy were used in this study to establish normal reference intervals in this species. Only falcons that were not being trained for falconry were used because falconry training is known to induce physical and physiologic stress, and such environmental stressors are known to significantly affect acid-base balance in birds. (11) Blood gas analysis should be performed immediately after blood sampling because cellular metabolism has been reported to decrease the pH of blood by 0.01 pH units every 10 minutes, leading to falsely lowered blood pH values. (20) In the current study, blood gas analysis was performed on all the samples within 5 minutes after sampling.

Alterations including metabolic acidosis have been reported in other species of birds that were spontaneously ventilating under prolonged isoflurane anesthesia. (15) Furthermore, intermittent positive pressure ventilation has been reported to bring about significant alterations in the values of pH, [Pco.sub.2], HC[O.sub.3.sup.-], and [Tco.sub.2] compared with spontaneous ventilation in birds under isoflurane anesthesia. (15) Although the values obtained under these conditions need not be representative of the values that may be obtained in a normal physiologic resting state for the species, they are of significant value to the avian clinical practitioner. Therefore, the current study was conducted on spontaneously ventilating birds, and sampling was done immediately after induction with isoflurane anesthesia.

In human, canine, and feline medicine, acidemia is defined as a blood pH below 7.35, whereas a pH above 7.45 is considered alkalemia. In acid-base disorders, both respiratory and metabolic components may contribute to acidosis and alkalosis, and these components may also have a role in the compensation of these disorders. However, because overcompensation rarely occurs under physiologic conditions, the blood pH alteration usually occurs in the same direction as the primary disorder. (4) Although no significant difference was found between the temperature-corrected values of pH from arterial blood and venous blood in our study, Bland-Altman plots showed that temperature-corrected venous pH slightly underestimated the temperature-corrected arterial pH. However, the bias and the 95% limits of agreement did not seem to be relevant from a clinical point of view, indicating that the 2 values may be used interchangeably. Arterial blood pH has been reported to be alkaline at around 7.5 in most species of birds. (4) Mean arterial pH reference intervals in nonanesthetized blue-fronted Amazon parrots (Amazona aestiva) was reported to be 7.452 [+ or -] 0.048, (14) whereas mean temperature-corrected venous pH reference intervals in nonanesthetized African grey parrots (Psittacus erithacus) was reported to be 7.256 [+ or -] 0.077. (4) In our study, the arterial pH values obtained after temperature correction (7.42 [+ or -] 0.07) were significantly lower than the values found before temperature correction (7.49 [+ or -] 0.07). The pH values obtained before temperature correction in venous blood (7.48 [+ or -] 0.08) were comparable, from a clinical perspective, to the values obtained in earlier studies with falcons (7.47 [+ or -] 0.04), (9) although there were different methodologies involved in these studies. Conversely, the temperature-corrected pH values in venous blood in our study were lower (7.42 [+ or -] 0.08). The temperature-correction formula used in the analyzer was established for human and mammalian patients. However, this formula was found to have a significantly high correlation in pigeons (Columba livia)n with a mean cloacal temperature of 42.1[degrees]C and was, therefore, assumed to be applicable to falcons in the current study. Since this temperature-correction formula has not yet been validated in most species of birds, including falcons, it may have influenced the results of our study. Although metabolic acidosis is more common in small-animal medicine, it has been suggested that the opposite may be true in birds, particularly in training falcons. (9) Results of this study prove that further investigations on temperature-corrected pH values and other blood gas parameters in falcons under training stress may be needed to validate or discharge this theory.

The [Pco.sub.2] represents the respiratory component of the acid-base balance. The [Pco.sub.2] increases (>45 mm Hg) with hypoventilation (from anesthesia, sedation, altered breathing mechanics, and upper or lower airway obstruction) and causes respiratory acidosis. Hyperventilation (from hypoxemia, pulmonary disease, anxiety, increased mechanical ventilation, or in compensation for metabolic acidosis) leads to a decreased [Pco.sub.2] value (<35 mm Hg) resulting in respiratory alkalosis. (4) Mean arterial [Pco.sub.2] reference intervals in nonanesthetized blue-fronted Amazon parrots was reported to be 22.1 [+ or -] 4.0 mm Hg, (14) whereas mean temperature-corrected venous [Pco.sub.2] reference intervals in non anesthetized African grey parrots was reported to be 35.7 [+ or -] 7.5 mm Hg. (4) In our study, the temperature-corrected values of [Pco.sub.2] in both arterial and venous blood were significantly higher than the corresponding values before temperature correction, and there were no significant differences between temperature-corrected [Pco.sub.2] values obtained from arterial and venous blood. Bland-Altman plots showed that temperature-corrected venous [Pco.sub.2] slightly underestimated temperature-corrected arterial [Pco.sub.2]. However, the bias and 95% limits of agreement do not seem relevant from a clinical perspective, suggesting that these values may be used interchangeably. Venous [Pco.sub.2] values obtained in our study (29.47 [+ or -] 5.2 mm Hg) before temperature correction were comparable from a clinical viewpoint to the values obtained (without temperature correction) previously in falcons (27.0 [+ or -] 4.5 mm Hg),12 whereas our results after temperature correction were higher (35.45 [+ or -] 6.07 mm Hg).

Arterial [So.sub.2] and [Po.sub.2] values in nonanesthetized blue-fronted Amazon parrots were reported as 96.2% [+ or -] 1.1% and 98.1 [+ or -] 7.6 mm Hg, respectively. (14) Venous temperature-corrected [Po.sub.2] reference intervals in nonanesthetized African grey parrots have been reported to be 52.5 [+ or -] 5.6 mm Hg, whereas the [So.sub.2] values were 68.4% [+ or -] 10.1%. (4) The current study was done in gyr falcons under anesthesia with isoflurane delivered in 100% oxygen. Although values of venous [So.sub.2] (98.56% [+ or -] 0.97%) and arterial [So.sub.2] (99.86% [+ or -] 0.4%) were significantly different in our study, clinically, these values differ minimally. Therefore, [So.sub.2] values cannot be used by the clinical practitioner to differentiate arterial blood from venous blood when samples are obtained from birds under anesthesia breathing 100% oxygen. Ranges of values similar to those obtained in our study for venous [So.sub.2] were also observed in earlier studies with falcons. (12) Temperature-corrected arterial and venous [Po.sub.2] values obtained in our study differed significantly from the values obtained before temperature correction. Bland-Altman plots revealed that temperature-corrected venous [Po.sub.2] underestimated temperature-corrected arterial [Po.sub.2], and the bias as well as the 95% limits of agreement seemed to be important from a clinical perspective. Temperature-corrected arterial [Po.sub.2] values (203.68 [+ or -] 25.56 mm Hg) differed significantly from similarly temperature-corrected venous [Po.sub.2] values (140.26 [+ or -] 21.1 mm Hg) and may be used for differentiating arterial blood from venous blood in healthy gyr falcons under isoflurane anesthesia.

The mean arterial HC[O.sub.3.sup.-] reference interval in nonanesthetized Amazon parrots was reported to be 14.8 [+ or -] 2.8 mmol/L, (14) whereas the mean venous HC[O.sub.3.sup.-] reference interval in nonanesthetized African grey parrots was reported to be 15 [+ or -] 2.4 mmol/L. (4) Arterial and venous HC[O.sub.3.sup.-] values obtained in the current study did not vary significantly from each other, and the venous HC03- values (22.4 [+ or -] 4.0 mmol/L) were comparable from a clinical perspective to the values observed in other studies in falcons (20.6 [+ or -] 2.0 mmol/L), (12) despite the difference in methodologies among studies.

Unlike HC[O.sub.3.sup.-], which is calculated from pH and [Pco.sub.2], BE values are independent of respiratory activity and, therefore, help to differentiate between respiratory and metabolic components. The BE value is also useful for calculating the amount of buffer required to treat patients with acidosis. (4) Arterial BE values in nonanesthetized Amazon parrots were reported to be -7.9 [+ or -] 3.1 mmol/L. (14) Arterial BE values (0.36 [+ or -] 5.1 mmol/L) from gyr falcons in our study did not differ significantly from venous BE values (-0.93 [+ or -] 4.9 mmol/L). In addition, the venous BE values in our study were comparable clinically to those observed in previous studies in falcons (-3.0 [+ or -] 2.0 mmol/L), (12) regardless of the difference in methodologies among studies.

Values of [Na.sup.+] and [K.sup.+] have been shown to differ significantly based on the assay method. (10) Although the values of venous [Na.sup.+] in our study (148 [+ or -] 1.81 mmol/L) were generally in the same range as those observed in previous studies in falcons, (9,12) these values differed significantly from values of arterial [Na.sup.+] (146.46 [+ or -] 1.79 mmol/L). Further studies are needed to explain the relevance of this finding. Arterial and venous [K.sup.+] values did not differ significantly in our study, and the venous [K.sup.+] values were comparable, from a clinical perspective, to those observed in previous studies in falcons. (9,12)

Hematocrit is measured by conductivity in the iSTAT 1 point-of-care blood gas analyzer. In previous studies in chickens and falcons, the values derived with i-STAT 1 correlated acceptably with standard laboratory-derived values. (2,9,12) However, hematocrit values in red-tailed hawks (Buteo jamaicensis) and Caribbean flamingos (Phoenicopterus ruber) were consistently underestimated with the i-STAT 1 when compared with values derived from standard methods. (10,20) When venous hematocrit values derived with i-STAT 1 in our study were compared with values obtained by the microhematocrit method, we observed that iSTAT 1 significantly underestimated hematocrit. The difference in the measured values of hematocrit by the 2 methods may be because i-STAT 1 analyzers are calibrated to match the measurements of microhematocrit tubes containing human whole blood mixed with the anticoagulant tripotassium ethylenediaminetetraacetic acid. This anticoagulant has been known to shrink human red blood cells because of an osmotic pressure gradient, leading to artificially lowered hematocrit values. In addition, the i-STAT 1 measures hematocrit by conductivity, which can be affected by the lower total serum protein seen in most species of birds compared with humans. (4) In our study, hematocrit values did not differ significantly between arterial and venous blood.

In mammalian samples, the i-STAT 1 has been reported to underestimate the values of ionized calcium when values were >1.3 mmol/L. (20) In chickens, however, ionized calcium values measured by i-STAT 1 correlated within acceptable limits with values measured by standard methods. (2) Values of ionized calcium measured in our study did not differ significantly between arterial and venous blood. The values of ionized calcium in venous blood from gyr falcons in our study (1.05 [+ or -] 0.09 mmol/L) were lower than the values obtained by previous investigators (12) in gyr hybrid falcons (1.16 [+ or -] 0.14 mmol/L). However, in that study, a very different methodology was used involving induction with injectable anesthetics in addition to isoflurane in 100% oxygen as well as a different blood gas analyzer. Moreover, the data in that study were obtained from hunting birds that are usually under intense physical training, which also may have lead to the increased ionized calcium levels in these birds.

The data obtained from this study will help to establish reference intervals for arterial blood gas values in healthy gyr falcons under isoflurane anaesthesia. This research also highlights the importance of temperature-corrected values for pH, [Pco.sub.2], and [Po.sub.2] for accurate arterial and venous blood gas analysis in birds. However, the built-in temperature correction formula in the i-STAT 1 blood gas analyzer has not yet been validated in most species of birds, including falcons. More research needs to be conducted on blood gas analysis in hunting falcons that are under stress to study the acid-base disturbances that occur in these birds. Based on the absence of significant differences between arterial and venous values of temperature-corrected pH, temperature-corrected [Pco.sub.2], HC[O.sub.3.sup.-], and BE in our study, we can theorize that, in gyr falcons, and possibly in other avian species, arterial blood gas analysis can be replaced by venous blood gas analysis in clinical situations.

Acknowledgments: We thank Their Highnesses Sheikh Mohamed bin Rashid Al Maktoum and Sheikh Hamdan bin Mohammed Al Maktoum for their patronage and kind support to the Al Wasl Veterinary Clinic. We also thank all the staff of Al Wasl Veterinary Clinic for their support in data collection and analysis.

References

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(9.) Mckinney PA. Clinical applications of the I-Stat blood analyzer in avian practice. Proc Eur Conf Assoc Avian Vet. 2003:341-346.

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(12.) Arca-Ruibal B, Aguilar-Sanchez V, Silvanose C, et al. Blood gas values in venous blood of captive hunting falcons in the United Arab Emirates. Proc Eur Conf Assoc Avian Vet. 2007:459 461.

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(15.) Chemonges S. Effect of intermittent positive pressure ventilation (IPPV) on acid-base balance and plasma electrolytes during isoflurane anaesthesia in sulphur-crested cockatoos (Cacatua galerita galerita). Int J Anim Vet Adv. 2012;4(6):351-357.

(16.) Harms CA, Harms RV. Venous blood gas and lactate values of mourning doves (Zenaida macroura), boat-tailed grackles (Quiscalus major), and house sparrows (Passer domesticus) after capture by mist net, banding, and venipuncture. J Zoo Wildl Med. 2012;43(1):77-84.

(17.) Heatley JJ, Cary J, Russell KE, Voelker G. Clinicopathologic analysis of Passeriform venous blood reflects transitions in elevations and habitat. Vet Med Res Rep. 2013;4:21-29.

(18.) Desmarchelier M, Rondenay Y, Fitzgerald G, Lair S. Monitoring of the ventilatory status of anesthetized birds of prey by using end-tidal carbon dioxide measured with a microstream capnometer. J Zoo Wildl Med. 2007;38(1): 1-6.

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(22.) Malatesha G, Singh NK, Bharija A, et al. Comparison of arterial and venous pH, bicarbonate, [Pco.sub.2] and [Po.sub.2] in initial emergency department assessment. Emerg Med J. 2007;24(8):569-571.

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Raj Raghav, BVSc & AH, MYSc, GDipl (Avian), DABVP (Avian Practice), Rachael Middleton, BVSc, MRCVS, Rinshiya Ahamed, BSc, Raji Arjunan, MLT, and Valentina Caliendo, DVM, CertAVP (Zoo Med), MRCVS

From the Al Wasl Veterinary Clinic, Post Box 75565, Dubai, United Arab Emirates.

Table 1. Arterial and venous blood gas values in 30 healthy gyr
falcons under isoflurane anaesthesia with a mean cloacal
temperature of 41.23 [+ or -] 0.52[degrees]C.

                                         Arterial blood gas values

                                                          Percentiles,
Parameter                            Mean [+ or -] SD      2.5%-97.5%

pH                                  7.49 [+ or -] 0.07     7.34-7.62
p[H.sup.T]                          7.42 [+ or -] 0.07     7.27-7.54
[MATHEMATICAL EXPRESSION NOT        30.5 [+ or -] 5.2     21.45-39.95
  REPRODUCIBLE IN ASCII], mm Hg
[Pco.sub.2]t, mm Hg                 36.76 [+ or -] 5.8    26.62-48.65
[MATHEMATICAL EXPRESSION NOT       182.1 [+ or -] 22.22   138.9-224.55
  REPRODUCIBLE IN ASCII], mm Hg
[Po.sub.2], mm Hg                  203.7 [+ or -] 25.56   127.7-246.55
Base excess, mmol/L                 0.36 [+ or -] 5.1        -22.25
HC[O.sub.3.sup.-], mmol/L           23.6 [+ or -] 4.22     12.07-29.8
[Tco.sub.2], mmol/L                24.56 [+ or -] 4.33     12.5-30.7
[So.sub.2], %                       99.86 [+ or -] 0.4      98.2-100
[Na.sup.+], mmol/L (mEq/L)         146.5 [+ or -] 1.79      143-150
[K.sup.+], mmol/L (mEq/L)           3.35 [+ or -] 0.28      2.9-3.9
Ionized calcium
  mmol/L                            1.07 [+ or -] 0.06     0.97-1.18
  mg/dL                             4.28 [+ or -] 0.24     3.88-1.72
Glucose, mg/dL                     325.1 [+ or -] 17.58    290-363.5
Hematocrit, %                      41.03 [+ or -] 3.82      33-49.25
Hemoglobin, g/dL                    13.9 [+ or -] 1.3      11.2-16.75

                                           Venous blood gas values

                                                          Percentiles,
Parameter                            Mean [+ or -] SD      2.5%-7.5%

pH                                  7.48 [+ or -] 0.08     7.34-7.62
p[H.sup.T]                          7.42 [+ or -] 0.08     7.27-7.55
[MATHEMATICAL EXPRESSION NOT        29.47 [+ or -] 5.2    19.85-41.22
  REPRODUCIBLE IN ASCII], mm Hg
[Pco.sub.2]t, mm Hg                35.45 [+ or -] 6.07     24.6-50.27
[MATHEMATICAL EXPRESSION NOT       111.7 [+ or -] 20.5     73.75-160
  REPRODUCIBLE IN ASCII], mm Hg
[Po.sub.2], mm Hg                  140.3 [+ or -] 21.1      96-187.2
Base excess, mmol/L                 -0.93 [+ or -] 4.9       -20.5
HC[O.sub.3.sup.-], mmol/L           22.4 [+ or -] 3.99      11-27.9
[Tco.sub.2], mmol/L                 23.33 [+ or -] 4.0     11.5-28.75
[So.sub.2], %                      98.56 [+ or -] 0.97      95.5-100
[Na.sup.+], mmol/L (mEq/L)          148 [+ or -] 1.81       146-153
[K.sup.+], mmol/L (mEq/L)           3.27 [+ or -] 0.3       2.7-3.85
Ionized calcium
  mmol/L                            1.05 [+ or -] 0.09     0.88-1.24
  mg/dL                             4.2 [+ or -] 0.36      3.52-1.96
Glucose, mg/dL                     317.0 [+ or -] 17.07    279.5-353
Hematocrit, %                       42.1 [+ or -] 4.02       34-50
Hemoglobin, g/dL                   14.31 [+ or -] 1.36      11.6-17

Abbreviations: (T) indicates a temperature-corrected value;
[Pco.sub.2], partial pressure carbon dioxide; P[O.sub.2], partial
pressure of oxygen; HC[O.sub.3.sup.-], bicarbonate concentration;
[Tco.sub.2], total carbon dioxide concentration; [So.sub.2],
hemoglobin saturated with oxygen.
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Author:Raghav, Raj; Middleton, Rachael; Ahamed, Rinshiya; Arjunan, Raji; Caliendo, Valentina
Publication:Journal of Avian Medicine and Surgery
Article Type:Report
Date:Dec 1, 2015
Words:5108
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